Cutting tool assemblies for such applications as mining or road milling typically comprise a cutting tool, sometimes referred to as a cutting pick, rotatably mounted within a support block. The support block in turn is mounted onto a drum or other body, typically by welding, which in turn is driven by a suitable drive means. When a number of such support blocks carrying cutting tools are mounted onto a drum, and the drum is driven, the cutting tools will engage and break up the material sought to be mined or removed. The general operation of such a mining or construction machine is well known in the art.
It is also known to equip a cutting tool assembly with a spray nozzle for spraying fluid onto a cutting tool so as to reduce the potential for ignition of gases encountered during cutting or mining activities. U.S. Pat. No. 5,378,048, for example, discloses a water spray nozzle that is retained within a threaded bore of a pick box or support block using a resilient retaining ring. This nozzle is relatively complex in design and relatively costly to manufacture. Furthermore, the discharge end of the nozzle is contained within the bore of the pick box such that the nozzle does not limit wear of the pick box during use. Consequently, if the pick box is sufficiently worn away, it can no longer house the nozzle.
As another example, U.S. Pat. No. 5,392,870 discloses a cutting tool assembly including a spray nozzle that is completely contained within a bore of pick box. Consequently, this nozzle also does not limit wear of the pick box during use. In addition, water passages disposed in the pick box for providing water to the nozzle are configured such that they cannot be drilled out once the pick box is welded to a drum. As a result, when the passages become blocked, such as by calcium deposits, the cutting tool assembly is no longer useful for cutting operations that require a functioning spray nozzle.